Revised on August 13th, 2023 to add a known issue.

Release Date:August 8, 2023

Version:.NET Framework 3.5 and 4.8

The August 8, 2023 update for Windows 10 Version 21H2 and Windows 10 Version 22H2 includes security and cumulative reliability improvements in .NET Framework 3.5 and 4.8. We recommend that you apply this update as part of your regular maintenance routines. Before you install this update, see the Prerequisites and Restart requirement sections.

Summary

Security Improvements

CVE-2023-36899 - .NET Framework Remote Code Execution Vulnerability This security update addresses a vulnerability in applications on IIS using their parent application’s Application Pool which can lead to privilege escalation or other security bypasses. For more information see CVE 2023-36899.

CVE-2023-36873 - .NET Framework Spoofing Vulnerability This security update addresses a vulnerability where unauthenticated remote attacker can sign ClickOnce deployments without a valid code signing certificate. For more information see CVE-2023-36873.

Quality and Reliability Improvements

WPF

- Addresses an issue where XPS documents using LinkTarget aren't rendering properly.

Networking

- Addresses an issue where using proxy with continuous load may lead to memory leak resulting in high memory usage, or potentially OutOfMemoryException.

1Windows Presentation Foundation (WPF)

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

  • 5029648 Description of the Cumulative Update for .NET Framework 3.5, 4.8 and 4.8.1 for Windows 10 Version 21H2 (KB5029648)

  • 5029649 Description of the Cumulative Update for .NET Framework 3.5, 4.8 and 4.8.1 for Windows 10 Version 22H2 (KB5029649)

Known issues in this update

Product Version

Symptom

Resolution

Windows 11, version 22H2

After installing windows KB5028244, applications which were deployed using ClickOnce might begin to prompt for installation even when the ClickOnce apps are already installed and marked as “trusted”.

To mitigate the issue, see Windows 10, version 22H2 resolved issues.

Windows 11, version 21H2

After installing windows KB5029244, applications which were deployed using ClickOnce might begin to prompt for installation even when the ClickOnce apps are already installed and marked as “trusted”.

To mitigate the issue, see  Windows 10, version 21H2 resolved issues.

How to get this update

Install this update

Release Channel

Available

Next Step

Windows Update and Microsoft Update

Yes

None. This update will be downloaded and installed automatically from Windows Update.

Windows Update for Business

Yes

None. This update will be downloaded and installed automatically from Windows Update.

Microsoft Update Catalog

Yes

To get the standalone package for this update, go to the Microsoft Update Catalog website.

Windows Server Update Services (WSUS)

Yes

This individual .NET Framework product update will be installed, as applicable, by applying the operating system update. For more information about operating system updates see additional information about this update section.

File information

For a list of the files that are provided in this update, download the file information for cumulative update.

Prerequisites

To apply this update, you must have .NET Framework 3.5 or 4.8 installed.

Restart requirement

You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.

How to obtain help and support for this update

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